Getting a "Curtain Effect" with 7w JTech laser on X-Carve

Hey there! I have been running my JTech 7w laser on my X-Carve with X-Controller for about 3 weeks now and I was doing a test burn on a piece of cedar and I began to notice some vertical lines in the solid filled squares.

I looked back at some previous test pieces I have done and I can see it faintly on those also. (I think that the cedar is the softest material I have tested on and that is why it is more prominent.) I am not sure what may be causing this.

What I have tried.

  1. Cleaning all rails, bearing, wheels, etc.
  2. Checked that all V-Wheels are adjust appropriately.
  3. Check belt tension and adjusted accordingly. (Not to tight, not to loose as far as I understand)

I found a similar thread here but was closed.

Here are my GRBL settings if needed, and if I can provide anymore information, I would be more than happy!
$0=10

$1=255

$2=0

$3=3

$4=0

$5=0

$6=0

$10=0

$11=0.020

$12=0.002

$13=0

$20=0

$21=0

$22=1

$23=3

$24=25.000

$25=750.000

$26=250

$27=1.000

$30=1000

$31=0

$32=1

$100=40.000

$101=40.000

$102=188.976

$110=8000.000

$111=8000.000

$112=500.000

$120=500.000

$121=500.000

$122=50.000

$130=750.000

$131=750.000

$132=100.000